In the past, lubricating oil has been sprayed upwardly into a cooling dome and an annular cooling groove adjacent the underside of the piston crown for the purpose of cooling. Also, a ledge or splash sill has been provided for trapping some of the oil and for directing the trapped oil back into the groove to supplement the oil spray.
A problem exists in that the ledge is positioned at the outer periphery of the piston which causes interference with the oil spray and which also causes poor directing of the trapped oil back into the groove.
In view of the above, it would be advantageous to provide an oil cooled piston having a ledge or splash sill which does not interfere with the spray, which better directs trapped oil back into the groove and which overcomes the problems associated with the prior art.